Many of us were found staring up at the sky on Monday around 2:00 PM in Iowa, as we marveled at the moon blocking the sun. But what effect does this phenomenon have on weather? Using a weather station from the ISU Soil Moisture Network, we can take a deeper look into how the eclipse effected various weather variables during the time of the event.
One notable effect of the eclipse was the development of a temperature inversion, measured at the station near Crawfordsville in southeast Iowa, displayed on this Iowa Environmental Mesonet daily feature. Typically, air temperature decreases with altitude, but during an inversion, there is a warmer layer of air existing above the cooler layer of air at the surface. This inhibits circulation of air at the surface. To measure conditions for an 
inversion, we place temperature sensors at 1.5, 5, and 10 feet above the surface. On the chart titled “10 Foot Temperature minus 1.5 Foot Temperature,” we can identify the existence of an inversion when the value is greater than zero.
Winds speeds also decreased during the time of the eclipse, weakening from almost 15 miles per hour in the morning, to around 5 miles per hour after 2:00 PM. Around 3:00 PM, wind speeds picked back up again.
Decreasing solar radiation allowed temperatures closest to the surface to cool quickly and wind speeds to slow. As the eclipse ended and the sun shone once again, surface temperatures warmed, wind speeds returned, and the inversion came to an end.
